The yellowing of the white edges of shoes may be due to stains and oxidation caused by prolonged use or storage. Here are some ways that may help you deal with the yellowing of the white edges of your shoes:
1. Cleaner cleaning: Use a cleaner suitable for the shoe material, which can be a special shoe cleaner or a cleaning solution mixed with mild soapy water. After soaking the shoe with a soft brush or sponge, gently wipe the white side of the shoe, and then wipe it clean. Remember to test on less visible areas before washing to make sure the detergent won't cause damage to the shoes.
2. Bleach treatment: For the white edge of white shoes, you can consider using diluted bleach to treat. First dilute the bleach to the appropriate concentration in a ventilated environment (usually 10 parts water: 1 part bleach), and then gently wipe the white edge of the shoe with a cotton ball or brush. When done, wash the shoes thoroughly to make sure the bleach is completely removed.
3. Oxygenic bleach: Oxygenic bleach is a non-chlorine bleach that can be used to treat yellow stains on the white edges of shoes. Apply bleach to the yellow stain according to the product instructions, then gently scrub. When finished, wipe it clean with a damp cloth and make sure to remove any remaining bleach completely.
Please note that the above method may be different for different materials of shoes (such as leather, cloth, synthetic materials, etc.). Before using any cleaning agent or bleach, confirm the specific shoe material that is applicable to you and follow the product instructions and warnings.
In addition, regular washing and proper protection of your shoes can prevent the white edges from turning yellow. Avoiding exposure to sunlight or wet environments can also reduce the likelihood of yellowing.